With today's vibrant technology marketplace, industry competition and consumer demand spurs manufacturers to continually improve the performance of their electronic devices. Increases frequently occur in many areas such as processing speed, storage capability, compactness, and functionality. Unfortunately, there are tradeoffs, as advances in one area often come at the expense of performance in another area. As one example, functionality and compactness oppose each other in many cases. Additions of new circuit functions typically require larger processors, greater storage size, and a larger overall package. Conversely, size reductions often come at the expense of processing speed, memory, or functionality.
This problem is especially acute with compact wireless telephones, which are more useful, marketable, and functional when their internal circuitry is capable of exchanging data with a diverse assortment of peripheral devices. One example such an internal circuit is a mobile baseband integrated circuit (IC), which serves as a central signal-processing element in a wireless telephone. To satisfy consumer requirements, it may be desirable for the mobile baseband IC to communicate with peripheral devices of diverse communications formats, such as stereo voice (e.g., MP3 sound), mono voice (e.g., audio codec), Bluetooth (to communicate with nearby wireless consumer devices), radio frequency (RF) formats (for an analog chipset for utilizing traditional “analog” cellular bands), and others. Peripheral devices include not only devices external to the wireless telephone itself, but also any circuitry internal to the wireless telephone and external to the baseband IC. To achieve broader compatibility with all of these diverse peripheral devices, and ultimately increase functionality, engineers are forced to add a new interface circuit for each different communications protocol (format) that needs to be supported. Clearly, these added interface come at the expense of circuit compactness as well as increases the cost of the design.
To preserve compactness while providing some degree of functionality, some wireless engineers design chips that are compatible with a selected number of the most popular peripherals. For those telephone consumers requiring a greater level of functionality, this approach may not be entirely satisfactory. This approach can also present future difficulties to the engineers, when they are required to design and manufacture a new circuit each time a decision is made to communicate with a new peripheral. Adding the necessary hardware interface circuits incurs costs in designing, tooling, and manufacturing the circuit all over again.
Another problem presented by prior art interface circuits is that they are typically designed such that they are not modifiable (e.g., hardware design) once designed. This is a concern for example if a new multi-media card (MMC) that could have been used by the wireless telephone is introduced but the communications protocol used by the new MMC has been updated and is no longer compatible with the MMC interface circuit supported by the wireless telephone. Consequently, known multi-peripheral interface circuits are not completely adequate for some applications due to some of the problems previously mentioned.